Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 UID: 0 PID: 24465 Comm: syz.5.5701 Not tainted 6.16.0-rc3-next-20250623-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:pidfs_free_pid+0xaf/0x140 fs/pidfs.c:162
Code: f0 ff ff 73 e4 43 80 3c 3c 00 74 08 4c 89 f7 e8 a7 1b de ff 49 83 3e 00 0f 85 84 00 00 00 e8 08 f2 79 ff 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 82 1b de ff 4c 8b 33 4d 85 f6 74
RSP: 0000:ffffc90000a08b90 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8880277d9e00
RDX: 0000000000000100 RSI: 0000000000000001 RDI: ffff888075fae370
RBP: 0000000000000001 R08: ffff888075fae303 R09: 1ffff1100ebf5c60
R10: dffffc0000000000 R11: ffffed100ebf5c61 R12: 1ffff1100ebf5c6d
R13: ffffffff81a83684 R14: ffff888075fae368 R15: dffffc0000000000
FS:  00007f0eb986b6c0(0000) GS:ffff888125d25000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0eae80a000 CR3: 00000000508f6000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 put_pid+0x9c/0x130 kernel/pid.c:103
 rcu_do_batch kernel/rcu/tree.c:2582 [inline]
 rcu_core+0xca5/0x1710 kernel/rcu/tree.c:2838
 handle_softirqs+0x283/0x870 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5875
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 eb 03 02 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0000:ffffc90003007aa0 EFLAGS: 00000206
RAX: e765b4f989435100 RBX: 0000000000000000 RCX: e765b4f989435100
RDX: 0000000000000000 RSI: ffffffff8db7f137 RDI: ffffffff8be322c0
RBP: ffffffff822f207d R08: 0000000000000000 R09: ffffffff822f207d
R10: dffffc0000000000 R11: fffffbfff3360624 R12: 0000000000000002
R13: ffffffff8e13dea0 R14: 0000000000000000 R15: 0000000000000246
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:841 [inline]
 page_table_check_set+0x1aa/0x730 mm/page_table_check.c:112
 page_table_check_ptes_set include/linux/page_table_check.h:76 [inline]
 set_ptes+0x231/0x240 include/linux/pgtable.h:292
 do_anonymous_page mm/memory.c:5140 [inline]
 do_pte_missing mm/memory.c:4267 [inline]
 handle_pte_fault mm/memory.c:6087 [inline]
 __handle_mm_fault+0x3c2c/0x5620 mm/memory.c:6230
 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6399
 do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7f0eb8850d50
Code: 39 4f 08 72 4c 8d 4d ff 85 ed 74 33 66 0f 1f 44 00 00 48 39 f0 72 1b 4d 8b 07 49 89 c1 49 29 f1 47 0f b6 0c 08 45 84 c9 74 08 <45> 88 0c 00 49 8b 47 10 48 83 c0 01 49 89 47 10 83 e9 01 73 d3 41
RSP: 002b:00007f0eb986a4a0 EFLAGS: 00010202
RAX: 000000000060a000 RBX: 00007f0eb986a540 RCX: 0000000000000063
RDX: 00000000000003ff RSI: 0000000000000400 RDI: 00007f0eb986a5e0
RBP: 0000000000000064 R08: 00007f0eae200000 R09: 0000000000000049
R10: 00002000000097c2 R11: 0000000000009762 R12: 0000000000000301
R13: 00007f0eb8a2c120 R14: 0000000000000013 R15: 00007f0eb986a5e0
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:pidfs_free_pid+0xaf/0x140 fs/pidfs.c:162
Code: f0 ff ff 73 e4 43 80 3c 3c 00 74 08 4c 89 f7 e8 a7 1b de ff 49 83 3e 00 0f 85 84 00 00 00 e8 08 f2 79 ff 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 82 1b de ff 4c 8b 33 4d 85 f6 74
RSP: 0000:ffffc90000a08b90 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8880277d9e00
RDX: 0000000000000100 RSI: 0000000000000001 RDI: ffff888075fae370
RBP: 0000000000000001 R08: ffff888075fae303 R09: 1ffff1100ebf5c60
R10: dffffc0000000000 R11: ffffed100ebf5c61 R12: 1ffff1100ebf5c6d
R13: ffffffff81a83684 R14: ffff888075fae368 R15: dffffc0000000000
FS:  00007f0eb986b6c0(0000) GS:ffff888125d25000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0eae80a000 CR3: 00000000508f6000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	f0 ff                	lock (bad)
   2:	ff 73 e4             	push   -0x1c(%rbx)
   5:	43 80 3c 3c 00       	cmpb   $0x0,(%r12,%r15,1)
   a:	74 08                	je     0x14
   c:	4c 89 f7             	mov    %r14,%rdi
   f:	e8 a7 1b de ff       	call   0xffde1bbb
  14:	49 83 3e 00          	cmpq   $0x0,(%r14)
  18:	0f 85 84 00 00 00    	jne    0xa2
  1e:	e8 08 f2 79 ff       	call   0xff79f22b
  23:	48 89 d8             	mov    %rbx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	48 89 df             	mov    %rbx,%rdi
  34:	e8 82 1b de ff       	call   0xffde1bbb
  39:	4c 8b 33             	mov    (%rbx),%r14
  3c:	4d 85 f6             	test   %r14,%r14
  3f:	74                   	.byte 0x74